When opening HTML, CTP or another PHP-HTML files in Aptana Studio 3, i found that all using bold which is annoying for me. So, to make it to be normal fonts :

1. Go to Aptana Studio menu -> “Window Menu”

2. Type “Themes” on left search box.

3. Find element “text.html.basic” and change it “Bold” style by click it.

4. Problem solved!